Distributions of Pu, Am and Cs in margin sediments from the western Mediterranean (Spanish coast)

Continental margins are important areas to be considered when studying the distributions and depositions of pollutants, both conventional and radioactive. Coastal sediments accumulate most of those contaminants which can be introduced following atmospheric and/or fluvial pathways. Moreover, their residence times within the water column are usually shortened due to their affinity to associate with the downward falling particulate matter, more abundant at shallower depths. In this paper the distribution profiles and inventories of plutonium, americium and cesium are detailed, providing useful information about recent sedimentation phenomena such as sediment mixing, slumping processes and bioturbation. Unsupported 210Pb data are used as reliable indicators of enhanced/reduced deposition events. Also, the calculated inventories have enabled the estimation of the radiological contribution of the Spanish Mediterranean margin to the total radioactivity deposited onto the Mediterranean sea floor.

[Toxic activity of Penicillium citrinum metabolites on Mus musculus mice]

The aims of this work were to study the influence of secondary metabolites produced by a Penicillium citrinum strain. Mus musculus mice were fed with a diet containing those metabolites to determine both its influence on their development and the pathological and biochemical changes on experimental animals. Male and female including pregnant females, were studied. One group received commercial feed (A.B.) to which the citrinin- producing mould had been added (LF), another received A.B. contaminated with commercial citrinin (LC). The last group received noncontaminated feed (LT). The animals were weighed weekly, and sacrificed after sixty days, so that they could be studied both macro and microscopically. In LF and LT mice, haematological analysis was carried out and hemosiderin was looked for in urine. The diet of the newborne mice, after weaning, was identical to that of their parent. The treated animals (LF and LC) showed morphological alterations, a significant decrease in weight and morphologic alterations and hemosiderin granules were detected in some of their organs. In LT all breeds survived, none of the mice showed neither macro nor microscopic anomalies and had normal biochemical parameters. Fewer breeds in LF survived, male infertility was detected and some of their haematologic parameters were also measurably lower.

Structure and evolution of the mitochondrial DNA complete control region in the Drosophila subobscura subgroup

The complete A + T-rich region of mitochondrial DNA (mtDNA) has been cloned and sequenced in the species of the Drosophila subobscura subgroup D. subobscura, D. madeirensis and D. guanche. Comparative analysis of these sequences with others already published has identified new sequence motifs that are conserved in Drosophila and other insects. A putative bi-directional promoter and a stop signal are proposed to be involved in the primary mtDNA strand replication of Drosophila. This region strongly resolves relationships of the species included in a phylogenetic analysis, both for closely related species and also at deeper phylogenetic levels when only the left and central domains are taken into account.

Mitochondrial DNA characterisation of European isolates: the Maragatos from Spain

Mitochondrial DNA analysis confirms that Maragatos from Spain are a genetically isolated human group. Genetic distances between Maragatos and the comparison samples are significantly different even with the León sample (P<0.001) which shares the same geographic area as the Maragatos. Although the north-African haplogroup U6 is present in them, their attributed Berber origin is weakened, as this haplogroup is also detected in surrounding populations with which, in addition, Maragatos have the smaller genetic distances. These U6 haplotypes are ascribed to a pre-historic African colonisation that influenced all the Iberian Peninsula. The presence of Neolithic haplogroups in this sample suggests that their isolation culture was not absolute until recent times.

Optimization and evaluation of atomic emission gas chromatographic detection for nitrogen using the 388 nm molecular emission spectral band

Nitrogen determination by gas chromatography with atomic emission (microwave-induced plasma) detection (GC-AED) has been accomplished using the 174 nm atomic emission line, but with very limited selectivity and sensitivity. Nitrogen can also be detected using the cyanogen (CN) molecular band at 388 nm. A commercial GC-AED system was modified to allow the use of the 388 nm line for nitrogen detection, giving an improvement of 100-fold in sensitivity and selectivity, when compared with the 174 nm mode. Limits of detection of 10 pg/s were common, representing a 10-fold improvement. Compound-independent behavior was found for the system, working with optimum operating conditions, while instrumental problems were clearly reflected by a drastic compound dependent behavior. Response factors showed an important dependency upon the concentration of the element present. This dependency affected the accuracy of the determination of empirical formulae using GC-AED.

Northwest African distribution of the CD4/Alu microsatellite haplotypes

We have analysed a linked microsatellite/Alu polymorphism at the CD4 locus (CD4/Alu) in 666 chromosomes from samples of the Iberian Peninsula, Northwest Africa, and West sub-Saharan Africa. The Iberian Peninsula differs from other European populations by its higher levels of haplotype diversity (0.75), and weaker association between the microsatellite allele 90 and Alu(-) chromosomes. These results are explainable by a substantial gene flow from Northwest Africa. Significant geographic clines for the five major haplotypes suggest a south to north migration from sub-Saharan Africa into Northwest Africa. In spite of this, the consistent presence of haplotype 110(-) in this area is congruent with an ancient and autochthonous human presence in Northwest Africa.

X-Ray structure of cytotoxic trans-[PtCl(2)(dimethylamine)(isopropylamine)]: interstrand cross-link efficiency, DNA sequence specificity, and inhibition of the B-Z transition

We report here the X-ray structure of cytotoxic trans-¿PtCl(2)(dimethylamine)(isopropylamine). This trans-platinum compound crystallizes in the monoclinic system, with Z = 8, in the spatial group C2/c with unit cell parameters a = 19.862(17) A, b = 6. 581(3) A, c = 18.563(3) A, alpha = 90 degrees, beta = 119.16(3) degrees, gamma = 90 degrees, V = 2119(2) A(3), rho = 2.321 Mg/m(3), R = 0.0505, and R(w) = 0.1166 on the basis of 2339 independent reflections. To our knowledge this is the first report of the crystal structure of a biologically active trans-platinum compound containing different aliphatic amines. The DNA binding mode of trans-¿PtCl(2)(dimethylamine)(isopropylamine) may be a consequence of the spatial disposition of the dimethylamine and isopropylamine ligands around the trans-Pt(II) center. We have found that trans-¿PtCl(2)(dimethylamine)(isopropylamine) readily forms DNA interstrand cross-links. In addition, the compound shows binding affinity toward alternating purine-pyrimidine sequences and inhibits the B-Z transition. These particular DNA binding properties might be related to the capacity of trans-¿PtCl(2)(dimethylamine)(isopropylamine) for inducing some selective killing in a H-ras overexpresssing cell line.

Loss of dopamine uptake sites and dopamine D2 receptors in striatonigral degeneration

To explore the mechanisms underlying L-dopa response, we studied, by postmortem autoradiography, selective makers of dopamine presynaptic terminals, [3H]WIN 35428, and dopamine D2 receptors, [3H]nemonapride, in the putamen of four Parkinson's disease (PD) and one striatonigral degeneration (SND) neuropathologically confirmed brains as compared with six matched control brains. Dopamine uptake transporter was dramatically decreased (> 90%) both in PD and SND striatum. Dopamine D2 receptors were preserved in PD, but clearly reduced (> 76%) in the SND putamen. These data confirm that L-dopa response is closely associated with the preservation of striatal dopamine D2 receptors.

Apoptosis induction and inhibition of H-ras overexpression by novel trans-[PtCl2(isopropylamine)(amine')] complexes

Hitherto, it has been generally accepted as a paradigm of the biochemical pharmacology of platinum antitumor drugs that a cis configuration of the leaving groups is necessary for antitumor activity of platinum compounds. However, it has been recently observed that certain trans-platinum complexes have both in vitro and in vivo antitumor activity. We previously reported the synthesis, characterization and cytotoxic activity against ras-transformed cells of several trans-[PtCl2LL'] complexes where L and L' are asymmetric aliphatic amines (L = dimethylamine and butylamine, L' = isopropylamine). The results reported in this paper show that the compounds trans-[PtCl2(isopropylamine)(dimethylamine)] and trans-[PtCl2(isopropylamine)(butylamine)] kill Pam 212-ras cisplatin resistant cells through apoptosis induction. Moreover, Western blot data show that both compounds inhibit overexpression of H-ras oncogene in Pam 212-ras cells. Altogether, these data indicate that, in contrast with cis-DDP, the apoptotic activity of these novel trans-Pt(II) compounds in ras-transformed cells is associated with their ability to abolish ras-overexpression.

Phylogeographic patterns of mtDNA reflecting the colonization of the Canary Islands

Although the Canary Islands were settled by humans, possibly of Berber origin, as late as 2500 years ago, the precise course and numbers of early migrations to the archipelago remain controversial. We have therefore analysed mtDNA variation (HVS-I as well as selected RFLP sites) in 300 individuals from the seven Canary Islands. The distribution and variation across the islands in a specific mtDNA clade of Northwest African ancestry suggest that there was one dominant initial settlement process that affected all the islands, from east to west. This indicates that a certain genetic affinity of present-day Canary Islanders to Northwest African Berbers mainly stems from the autochthonous population rather than slaves captured on the neighbouring African coast. The slave trade after the European conquest left measurable, though minor, traces in the mtDNA pool of the Canary Islands, which in its majority testifies to the European immigration.

Mitochondrial DNA analysis of northwest African populations reveals genetic exchanges with European, near-eastern, and sub-Saharan populations

Genetic studies have emphasized the contrast between North African and sub-Saharan populations, but the particular affinities of the North African mtDNA pool to that of Europe, the Near East, and sub-Saharan Africa have not previously been investigated. We have analysed 268 mtDNA control-region sequences from various Northwest African populations including several Senegalese groups and compared these with the mtDNA database. We have identified a few mitochondrial motifs that are geographically specific and likely predate the distribution and diversification of modern language families in North and West Africa. A certain mtDNA motif (16172C, 16219G), previously found in Algerian Berbers at high frequency, is apparently omnipresent in Northwest Africa and may reflect regional continuity of more than 20,000 years. The majority of the maternal ancestors of the Berbers must have come from Europe and the Near East since the Neolithic. The Mauritanians and West-Saharans, in contrast, bear substantial though not dominant mtDNA affinity with sub-Saharans.

Molecular diagnosis of alkaptonuria mutation by analysis of homogentisate 1,2 dioxygenase mRNA from urine and blood

Alkaptonuria (AKU) is caused by lack of homogentisate 1, 2 dioxygenase (HGO) activity. From the complete sequence of a human HGO cDNA, primers were designed in order to obtain reverse transcription-polymerase chain reaction products from tissues with ectopic transcription amenable to diagnostic analysis. A search for mutations in HGO cDNA was performed in an AKU family using urine and blood samples. The results show complete cosegregation (Z = 6.32; theta = 0) between a C-->T transition at position 817 of the human HGO cDNA and AKU. This mutation predicts a Pro-->Ser replacement at amino acid 230, and generates an EcoRV site.

Population genetic structure and colonization sequence of Drosophila subobscura in the Canaries and Madeira Atlantic Islands as inferred by autosomal, sex-linked and mtDNA traits

The genetic structure in Atlantic Islands and continental populations of Drosophila subobscura has been studied using autosomal and sex-linked allozymes and mitochondrial DNA (mtDNA) haplotypes. From the data it is deduced that whereas the Canary islands have long been isolated, the neighboring island of Madeira has been subjected to continuous migration from the mainland. In addition, sex-linked allozymes and mtDNA data show a large divergence between the geologically younger western islands of the Canarian Archipelago and the older central ones, finding strong founder effects in the former. Divergence rates of sex-linked and mitochondrial genes relative to autosomic loci several times higher than expected under neutrality have been explained by differential migration between sexes. The Canarian Archipelago colonization fits in well with a stepping-stone model of a directional east-west migration that parallels the geological origin of these Islands.

Sub-Saharan influence on the Canary Islands population deduced from G6PD gene sequence analysis

In a screening of glucose-6-phosphate dehydrogenase (G6PD) A variants in the Canary Islands and northwest African populations by electrophoresis and posterior gene sequencing, the common A+ 376G and A- 202A/376G and the rare A- 376G/968C mutations were found. In addition, three new silent C-->T transitions have been detected at nucleotides 759 (exon 7), 1338 (exon 11), and 1573 (exon 13). Canary Island and North African samples share sub-Saharan haplotypes with Equatorial Guineans. The slave trade seems the most probable origin of the African haplotypes found in the Canary Islands.

Genetic relationship between the Canary Islanders and their African and Spanish ancestors inferred from mitochondrial DNA sequences

Nucleotide sequences of the hypervariable segment I of the control region of the mtDNA were determined in 101 individuals: 54 Canary Islanders, 18 North African Berbers, 18 Spanish mainlanders and 11 sub-Saharan Guineans. In spite of the fact that only members of the Fang tribe were analysed, nucleotide diversity in Guineans (theta x 100 = 2.33) is one of the highest found in African populations. Estimates of genetic contribution to the Canarians from their putative parental populations based on mtDNA (43.25 +/- 1.38% Berbers, 35.54 +/- 0.55% Spanish, 21.21 +/- 1.92% Guineans) showed an important North African substrate. These mtDNA results, when compared with data based on nuclear markers, point to a strong male female asymmetry, 75% of the Spanish nuclear contribution was due to males and practically all the Berber and Guinean was due to females. These results are in agreement with the way that the Canary Islands were conquered. Pairwise difference distributions in Guineans and Berbers are compatible with the model of populations in expansion. Departures from a Poisson distribution for the Canarians and Spanish can be explained by admixture and the way of sampling respectively.

[Neurological impairment in children with HIV infection]

We retrospectively checked 53 paediatric patients suffering from infection with human immunodeficiency virus (HIV) registered in our Centre between the years 1987 and 1993, and evaluated the appearance of HIV encephalopathy. We noted important neurological signs in eleven patients (20.7%) ten of whom had HIV infection via vertical transmission and one as a result of contamination from haemoderivatives. In this review we give a detailed description of neurological signs, the moment of onset of these signs and their possible relationship with the state of the HIV infection. We also analyzed the resulting neuroradiological findings as well as any abnormalities in cerebrospinal fluid. Follow-up period ranged from one month to two and a half years from the moment of onset of the appearance of encephalopathy. Although most of our patients showed a clear improvement after oral or intravenous treatment with zidovudine, this improvement generally proved to be short-lived. The mortality rate in our HIV encephalopathy series was 81.8%, this figure being reached two and a half years after encephalopathy. The appearance of neurological signs in HIV patients therefore represents a very gloomy prognostic factor in the evolution of the disease.

Autoradiographic demonstration of increased alpha 2-adrenoceptor agonist binding sites in the hippocampus and frontal cortex of depressed suicide victims

To examine directly in the brain the status of alpha 2-adrenoceptors in major depression, the specific binding of the agonist [3H]UK 14304 was measured by quantitative receptor autoradiography in the hippocampus and frontal cortex of suicide victims (n = 17) with a retrospective diagnosis of depression (n = 7) or other psychiatric disorders (n = 10) as well as of matched control subjects (n = 9). In suicide victims, a significant increase in the number of alpha 2-adrenoceptors was found in the CA1 field (40%) and dentate gyrus (20%) of the hippocampus and in the external layers I (33%) and II (31%) of the frontal cortex, compared with that in matched controls. In depressed suicide victims, the increase in alpha 2-adrenoceptors in the CA1 field (57%) was significantly greater (24%, p < 0.05) than that observed in the group of suicide victims with other diagnoses (26%). In the same depressed suicide victims, the increase in cortical alpha 2-adrenoceptors was restricted to layer I (34%) and it was equivalent to that found in layer I (33%) of suicide victims with other diagnoses. The results indicate that suicide is associated with increases in the high-affinity state of brain alpha 2-adrenoceptors adrenoceptors and that there is a pronounced localized increase of this inhibitory receptor in the hippocampus of depressed suicide victims.

Human enzyme polymorphism in the Canary Islands. VI. Northwest African influence

The genetic polymorphism of eight red cell enzymes was analyzed in population samples from the Northwest African Continent and from the South of Spain in order to study their genetic relationships with the Canarian population. The Moroccan, Berber and Spanish populations, although geographically more distant from the Canary Islands than the Saharan and Mauritanian ones, are genetically more closely related to the Canarian population. The glucose-6-phosphate dehydrogenase Gc allele earlier found only in the Canary Islands was detected in the Berber sample. The Spanish, Berber and African Black contributions to the Canarian hybrid population was estimated to 70, 20 and 10%, respectively.

Changes in aminergic receptors in a PSP postmortem brain: correlation with pathological findings

The state of different aminergic receptors was assessed, by quantitative autoradiography in tissue sections, in several representative brain regions from a typical progressive supranuclear palsy (PSP) patient and from 9 matched brains. The densities of muscarinic receptors were within control limits in most of the brain areas of this PSP brain. Serotonin1 receptors were clearly reduced only in areas with very relevant neuropathological damage, such as locus niger and globus pallidus. The density of D1 dopamine receptors in the caudate-putamen and frontal cortex of the patient was within control limits. By contrast, nigral D1 and striatal D2 dopamine receptors were dramatically reduced in the patient as compared to controls. Finally, alpha 2-adrenoceptors were clearly reduced in all the examined areas of this PSP patient as compared to control group. Both the potential role of these receptor changes in the pathophysiology of the clinical features of PSP and their correlation with the neuropathological findings of this PSP patient are discussed.

Autoradiographic demonstration of loss of alpha 2-adrenoceptors in progressive supranuclear palsy: preliminary report

We assessed, by quantitative autoradiography in tissue sections, the density of alpha 2-adrenoceptors in several representative brain regions from a typical progressive supranuclear palsy (PSP) patient and in 9 matched brains. The full agonist 3H-bromoxidine was used as a ligand. The density of alpha 2-receptors was dramatically reduced in all the examined brain areas of this PSP patient as compared to the control group. The locus ceruleus degeneration observed here is the most plausible explanation for this loss of alpha 2-receptors. Our data show that abnormalities in the noradrenergic system may justify some clinical features of the PSP clinical picture, this supporting the idea of further study of the clinical effects of noradrenergic drugs in PSP.

Latitudinal differences in sex chromosome inversions, sex linked allozymes, and mitochondrial DNA variation in Drosophila subobscura

Mitochondrial DNA, sex linked allozymes, and chromosome A gene arrangement data, from eight European natural populations of Drosophila subobscura, were analyzed to determine the existence of latitudinal clines. Strong north-south correlations with latitude were found for gene arrangements and for the Hbdh and 6Pgdh allozymes. Gametic associations between the A2 gene arrangement, the Hbdh96 and the 6Pgdh96 alleles, point out some kind of epistatic interaction. At mtDNA level, the Hae III, A variant did not show a previously found north-south clinal variation.